1. Technical Field
The disclosure relates to a lens manufacturing apparatus and a lens manufactured thereby.
2. Description of Related Art
Injection molding method is currently one of the best choice for mass production of lenses. Molten material is injected into a mold cavity of a mold apparatus under a high pressure. When the molding cavity is full, the cooled down and solidified molten material is shaped to produce a lens. Generally, a lens includes at least one convex or concave surface for converging or diverging transmitted light, which gives the lens a cross-sectional thickness varying from the periphery to the center. The varied cross-sectional thickness means that the molten molding material in the mold cavity is cooled down at different rates, where the thinnest parts are cooled before the thickest parts; as a result, this causes “sinks” in the lens, which produce molded-in stress that make the lens quite brittle.
Therefore, it is desirable to provide a lens manufacturing apparatus that can overcome the above problems, and a lens manufactured thereby.